


sun drenched

by wintersrose616



Series: sun warm, salt stain [4]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: (Dimitri is a mermaid and he has two dicks), Alternate Universe - Merpeople, Established Relationship, Explicit Sexual Content, M/M, Monsterfucking, Praise Kink
Language: English
Status: Completed
Published: 2020-08-06
Updated: 2020-08-06
Packaged: 2021-03-06 06:08:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,659
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25748671
Author URL: https://archiveofourown.org/users/wintersrose616/pseuds/wintersrose616
Summary: Dimitri forces his fingers to relax their death grip on the bedding, glancing away in embarrassment."I was just—. I am still getting used to it all."Sylvain hums, hands going to his hips, thumbs rubbing soothing circles against the sharp jut of his hip bone. "Do you want to stop?""No!" he says, quickly—far too quickly. Sylvain quirks a brow as he places featherlight kisses up his neck, tongue darting out to lick at the sweat gathering there. "I just—." He squirms, the press of Sylvain against him causing his hips to jerk despite himself. "I am unused to the one, is all," he admits, face feeling alight with flames.Sylvain's lips are against the soft spot behind his ear. He pauses there, and Dimitri wonders if he's made some sort of mistake. There have been many missteps of human tradition on his part, this entire situation new, a learning experience he and Sylvain are navigating together.When Sylvain pulls his lips away, Dimitri feels the gap like it's an uncrossable chasm, as if now that he’s spoken, he’s ruined it all."The 'one?'".Sylvain gets an up close and personal lesson in merfolk anatomy.
Relationships: Dimitri Alexandre Blaiddyd/Sylvain Jose Gautier
Series: sun warm, salt stain [4]
Series URL: https://archiveofourown.org/series/1779427
Comments: 8
Kudos: 118





	sun drenched

**Author's Note:**

  * For [KayNight](https://archiveofourown.org/users/KayNight/gifts).



_Overwhelming_ seems like a bland way to describe how he feels during their first time.

Dimitri’s laid out across Sylvain’s bed, his fingers twisted into the sheets, fabric wound so tight he’s fearful he’ll tear right through it, but his mind hones in on the heat of Sylvain’s mouth, the pressure of his fingers digging into his thighs, holding him open. Open, _exposed_ , as his length disappears into the wet clutch of Sylvain’s mouth. 

“I didn’t— _ah._ ” His breath catches on a gasp as Sylvain’s throat opens around him, taking him _deeper_. Dimitri has to stop looking, but he can’t, completely enraptured by the sight of Sylvain’s lips stretched around him, the furrow to his brow as he concentrates on what he’s doing, even further to the bite marks and bruises littering his neck and shoulders. 

“I didn’t— _anticipate_ —,” he manages to start again, “—it feeling like th _is_.” 

Sylvain pauses, lips pulled halfway up his cock, and when his eyes flick up through his lashes to meet his, Dimitri almost loses himself entirely. Sylvain pulls off of him completely, one hand pressing down on his stomach so he can’t buck up after him. His lips are red and shiny, spit and precome making a mess of his chin. His other hand lifts to push tangled, sweat curled hair from his face, drawing Dimitri's eye away from his face to the flex of his arm.

"Alright, I'm doing something wrong if you're still capable of complete sentences."

Dimitri is already certain he’s completely red—the splotchy blush across his chest is a give away entirely—but he feels even more heat burn through his face at the casual way Sylvain declares it, as if moments ago he didn’t have Dimitri’s cock down his throat. 

He forces his fingers to relax their death grip on the bedding, glancing away in embarrassment. 

"I was just—. I am still getting used to it all."

Sylvain hums, hands going to his hips, thumbs rubbing soothing circles against the sharp jut of his hip bone. "Do you want to stop?"

"No!" he says, quickly—far too quickly. Sylvain quirks a brow as he places featherlight kisses up his neck, tongue darting out to lick at the sweat gathering there. "I just—." He squirms, the press of Sylvain against him causing his hips to jerk despite himself. "I am unused to the one, is all," he admits, face feeling alight with flames.

Sylvain's lips are against the soft spot behind his ear. He pauses there, and Dimitri wonders if he's made some sort of mistake. There have been many missteps of human tradition on his part, this entire situation new, a learning experience he and Sylvain are navigating together.

When Sylvain pulls his lips away, Dimitri feels the gap like it's an uncrossable chasm, as if now that he’s spoken, he’s ruined it all.

"The _'one_?'" Sylvain asks, slowly, words picked carefully, his hands carefully guiding Dimitri's up to rest against his waist.

Dimitri's mouth opens, stammers shut again, his fingers flexing against the warm skin beneath his grip. "I, ah—."

_This_ he had thought would be common enough knowledge, but, then again, before meeting Sylvain, he had never paid any heed to humans bodies enough to _think_ about their genitalia. He opens his mouth, trying to figure out the best way to explain it, but Sylvain’s eyes light up with a realization that seems to crash around him like the morning tide. His lips part, and Dimitri watches as his pupils widen, leaving only a thin ring of burning amber around them.

“Holy shit,” he breathes, voice airy. “Oh, Sothis, darling, are you telling me when you’re in your shark form you’ve got two dicks?” 

The noise Dimitri makes is high-pitched, an embarrassed whimper as he turns his face away, fingers clenching and unclenching against Sylvain's hips. Sylvain’s hand catches his jaw before he can try to bury it in the bedding, turning him so he’s forced to look up at him. Dimitri does the next best thing, which is to squeeze his eye shut, but Sylvain’s tongue dipping in between his lips startles him into opening it again. 

It’s heated, as hungry as their kisses had been before Sylvain had slid down his body. By the time Sylvain pulls away, Dimitri’s panting, chasing after him when Sylvain draws back.

“That’s so hot." Sylvain's voice comes out as a gasp, his own chest billowing with his heavy breaths. “Next time you transform to go back to the Kingdom, you’ve got to fuck me with them.”

The possessive thrill that runs through him at the thought wars with the voice in the back of his head that screams _danger_ , but he doesn't have a chance to say anything to it before Sylvain's mouth is against his, teeth catching his bottom lip. Dimitri surges upwards, winding an arm around his waist, the other reaching up to tangle his fingers in his hair as he presses messy kisses away from his mouth, down his jaw, biting down against the muscle at his neck. Sylvain makes breathy noises above him as Dimitri's teeth catch deep enough in his skin to draw spots of blood to the surface that he licks away, lips smearing the rest of it down across his constellation of freckles.

Sylvain has always been chatty. Dimitri learns quickly that even with a cock inside him, he can still form sentences, despite Dimitri only being able to make choked off noises between moans of Sylvain's name as Sylvain moves himself, thighs flexing, knees tight against Dimitri's side. He _babbles_ , all about Dimitri, how much he loves him, how good he feels inside him, how _great_ it would be to feel both of his cocks in him, and Dimitri comes with his teeth digging into the flesh of Sylvain's shoulder, hands tight against him as he grinds out his pleasure. Sylvain _laughs_ out of all the things he could do, cock still hard and throbbing where it's trapped between their stomachs, Dimitri softening inside him. His breathless laugh is accompanied by open mouth kisses to Dimitri's temple, wet panted breaths rustling his hair.

"Feel good?"

" _Yes_." Dimitri's still trying to catch his breath, his hand lifting to trace the bloodied teeth marks in his skin, but Sylvain grabs it before his fingers can touch, guiding him back down.

"My turn?" he asks, still breathless, pupils still wide, and Dimitri is helpless to do anything but nod.

Sylvain pitches forward, face burying in Dimitri's neck as his hand moves over his cock, too drunk on pleasure to do more than mouth against Dimitri's salt stained skin as he hurdles over the edge, spilling across their stomachs.

Even as Sylvain and he tidy up, Dimitri's thoughts spiral into what _could_ be, the image of them in the shallows, waves lapping against them as Sylvain nestles in his lap, his claws holding him steady—it's almost too much just imagining it.

Except, Sylvain doesn't bring it up the first time he returns to the Kingdom, nor the second time, and by the third, Dimitri's chalked it up to something said in the heat of the moment, piled on top of Sylvain's other filthy whispers. Even if he cannot stop thinking about how it might feel to have Sylvain while in his _true_ form, he knows that, while Sylvain always says what he means, sometimes dirty talk is just that, whispered to chase each other over the edge.

The thought still fills Dimitri with a heady mixture of fear and arousal, but he does not bring it up, either. It's a thought he buries deep within his mind, locked away, something dangerous and dirty that he dare never speak aloud.

Because of this, Dimitri doesn't think much of it when Sylvain lingers along the shoreline with him. He's due back in the Kingdom later in the afternoon, but the morning had been nice enough that they left early to spend their last few hours before a week apart on the warm sands. Sylvain seems extra _squirmy_ after Dimitri's transformed, shifting consistently where he sits on the sands, watching as Dimitri pushes himself out into the deeper water to swim around and recover in familiar currents before he settles back against the tide line. Sylvain doesn't mention anything, nor does he seem to be in any state of discomfort, so Dimitri feels alright in not questioning him, letting him push their conversations while the waves lap gently against the sand.

They've barely been there an hour before Sylvain decides they don't need to keep talking. Dimitri doesn't have it in himself to complain when Sylvain transitions their chatting to kissing, pressing Dimitri down against the sand as his hands skate down his side, fingers smoothing along rough skin and the scales smattered at the top of his hips. He swings a leg up and over Dimitri, settling into his lap, and Dimitri's tail splashes water up in a nervous flick. Sylvain looks at him as if he holds the world atop his shoulders, the reason the sun rises and sets every day, heat lacing through every loving press of his mouth against Dimitri, every caress of his fingers along scaled hips, every harmless bite against his rough skin.

Even then, though, Sylvain doesn't seem content. Slow, lazy kissing turns hungry in the matter of moments, the gentle press of his fingers digging deeper, heated where they drag along scales and skin alike. Sylvain's lips catch on Dimitri's fangs, blood immediately pooling into their kiss. Dimitri pulls back, the scent of copper intoxicating, but Sylvain doesn't let him get far, tugging him back.

"Sylvain— _ah_ —"

"Hold on, sweetheart, hold on." 

Sylvain's breathless, smearing messy kisses up along Dimitri's cheekbone. When his teeth snag lightly against the fin that fans his face, Dimirti makes a noise close to a warble, hands tightening against Sylvain's waist, claws catching against fabric and almost tearing through. Sylvain's hands move, and Dimitri barely pays any heed to the rummaging he hears until he's sitting back on his haunches, settled back against Dimitri's scales. Sylvain looks at him, eyes smug, and Dimitri's eye narrows in on the bottle clutched in his grasp.

It's lube.

He looks up to Sylvain, startled, catching sight of his grin, the arousal clear in his gaze.

"I wanted to send you off in the best way," he says, before surging down again, the bottle being set aside in favour for his hands tangling in the salt curled waves of Dimitri's hair.

Sylvain grinds down against him, his cock thick and heavy where it's trapped in his damp clothes. Dimitri's mouth hangs open with a moan at the feel of him, hard and ready just for him. 

It's too much, and not enough. Sylvain's kisses are burning hot, all teeth and tongue, testing his limits against Dimitri's sharp fangs. When he pulls back, there's smeared messily across his lips, across his jaw and cheeks where Dimitri's kisses have streaked his blood. Sylvain already looks ravished, and Dimitri has never wanted anything more than he wants to be inside him.

Despite his desire, he can't stop the rush of shame that fills him when he slips from his sheath, but when Sylvain grinds down again, feels _both_ , his moan matches the deep growl that rumbles out of Dimitri's throat.

Embarrassment burns at his face, forces an apology halfway out of his mouth. "Sylvain, I—"

"Ssh, ssh, hold on, love." Sylvain presses a kiss to his temple, soft, too tender considering his hand is moving down. "I have a surprise for you."

He swings his thigh over, off of him, and his eyes land on where Dimitri's cocks rest, both hard and leaking against his scales. Dimitri feels heat rush through him, the urge to grab Sylvain so he can't look filling him, but Sylvain's eyes narrow in on them. 

Dimitri expects surprise, _disgust_. He expects to witness Sylvain changing his mind and leaving Dimitri here at the shore. He knows first hand how different his cocks look in this form, the tapered ridges coated in slick, leaving him wet and wanting as they curve up from his slit. They're nothing compared to what he's used to fucking Sylvain with, both cocks bigger and inhuman. 

Sylvain makes a noise, one that sends a shudder running through Dimitri regardless of his embarrassment. He brings his eye up to Sylvain's face, feeling the splotchy blush burn down his neck. Sylvain's not looking at him in fear or disgust—he looks at Dimitri's cocks like they're his own personal feast.

Dimitri's seen bloodlust, knows a single-minded focus, but seeing Sylvain— _Sylvain_ , the love of his life—looking at him like he is makes heat course through him. Dimitri wants nothing more than to tug him back, leave even more marks across his shoulders and neck to match the mottled bruises that are still healing. 

Sylvain moves out of reach as soon as Dimitri's claws outstretch towards him, slipping out of his shirt in an easy movement. Dimitri's eye tracks every movement of his muscles as they flex with the motion, before his gaze drops as Sylvain's hands go to his shorts, tugging them off, showing how hard he is as his cock curls towards his belly, the head already wet from beads of precome. Dimitri _growls_ before he can help himself, the noise ripping from his throat. Sylvain startles, just slightly, before his expression is replaced by a smug smirk.

"That's not your surprise," he says, voice teasing. He ignores Dimitri's claws reaching out for him, so Dimitri goes for the bottle half buried in the sand beside him. Sylvain is back on his lap quick enough, taking the lube from him, placating him with a devouring kiss when Dimitri growls at the theft. 

"As much as I love and trust you, sweetheart," he breathes when they part, lips slick with saliva and blood, "I don't want your claws in my ass."

Dimitri comes back to himself, feeling like he's been doused with ice water as the waves lap at his fin, but Sylvain grabs his hand, curling his finger so he's holding his knuckle propped up.

"I still haven't shown you your surprise," he murmurs, voice low.

With Sylvain's hand guiding, Dimitri's knuckle brushes down, and when it catches against his rim, Dimitri feels a groan escape him.

"You prepared?" he asks.

Sylvain grins, rubbing back against his knuckle. "I brought lube with me, babe, of course I prepared."

Dimitri nips against his neck at the tease. "When?" 

"In the shower."

A harsher bite, still controlled enough to not break the skin. The thought of Sylvain fingering himself open while Dimitri was paces away, none the wiser as he laid in bed that morning, fills him with a white-hot jealousy he can't explain.

"I would've let you help, but we don't do well in showers together," Sylvain says, looking quite pleased with himself as he pulls Dimitri's hand away. " _And_ I wanted to surprise you."

Before Dimitri can respond, Sylvain shifts, grinding back, one of Dimitri's cocks catching against his cheeks and he groans, dropping his head to press kisses against his face as Dimitri's hands reach up. His claws dig into firm muscle, leaving small punctures in the skin of Sylvain's thighs that he'll apologize for later— _later_ —because his mind is too focused on _SylvainSylvainSylvain_ and _mineminemine_ as his teeth drag lightly along his skin, not nearly enough to draw blood, but close, his jaw trembling with the desire to bite deep, but not daring to.

"Fu— _ck_." Sylvain's voice cuts off in a groan as he moves, lifting himself up on his knees high enough for his hand to slip around one of Dimitri's cocks. "Fuck, I want them both."

Dimitri moans at the thought, looking down. Sylvain's hands are almost as large as his, but where it encircles the base of his cock, it almost looks small. Dimitri feels his pupil thin at the thought of him being inside Sylvain, sheathed in tight warmth, and his claws dig in tighter.

Sylvain swears roughly at the feeling of his claws. "Hold on, hold on, I've gotta—."

His hands fumble for the bottle of lube and Dimitri busies himself with laving his tongue along Sylvain's chest, licking away the sweat that's gathered on his skin. Sylvain moans brokenly when his tongue circles a nipple, his hands still furiously trying to get the bottle opened. As soon as he succeeds, he squeezes some out onto his hand, cold drips landing on Dimitri's stomach and causing his muscles to twitch. Sylvain's hand smears the slick messily along Dimitri's cock and a growl reverberates through his chest at the sensation, quickly devolving into a moan when Sylvain sinks down, feeding Dimitri's cock to his hole slowly.

"Next time," Sylvain breathes, voice hitching when a ridge catches against the muscle. "Next time I'm gonna stretch myself to take both."

Dimitri's head falls back, Sylvain swallowing him inch by inch. His teeth gnash together as he tries to control himself, hands pressing cruel bruises into the sharp jut of Sylvain's hip bones. Sylvain's back bows, his hands supporting himself up, fists pressed to Dimitri's chest. Even with a cock buried in him, he manages to chatter, making promises about _next time_ and how good Dimitri feels inside him, and Dimitri can't stop himself from praising him in turn, Sylvain's words turning to nonsensical mewls and moans as Dimitri breathes about how beautiful he is, how well he's taking his cock. As soon as he's settled, pressed flush against the flared base of his cock, Dimitri's second one rubbing against the small of his back, Sylvain keens low in his throat. Dimitri unfurls his grip, smoothing his hands along Sylvain's thighs as he trembles, trying to adjust. His eye stays focused on Sylvain's face, the way his teeth are digging into his already bruised and battered bottom lip, eyes squeezed shut, red splotches across his cheeks and down his chest.

He's gorgeous, and Dimitri lifts a hand, claws carefully pushing his hair out of his face as he tells Sylvain as such, eliciting a broken moan rumbling from Sylvain's throat.

"Tell me, tell me, tell me," Sylvain pants, squeezing tight around him, milking his cock before he shifts up again, slowly starting to ride him.

Dimitri groans, one hand moving to slip under his thigh to help support him, the other tangling his claws carefully in the red waves of Sylvain's hair.

"You're so good for me, Sylvain," he all but growls as Sylvain sinks back down, grinding against him. "So good for me, beautiful, wonderful, love, you're taking me so well."

Sylvain chokes on a sob, and Dimitri starts to move in earnest when his legs give out. Sylvain whines, squirming atop him as Dimitri's tail rolls beneath them, thrashing in the water as he chases his pleasure. The hand that's snarled in his hair moves down, pressing his second cock against Sylvain, rutting against him as they move.

He knows exactly when his cock hits Sylvain's prostate, based on the way he squeezes tight, a broken, throaty whine falling from his lips as he pants out his pleasure. It doesn't take much more after that until Sylvain's gasping wetly in the crook of Dimitri's neck, coming untouched with a wail he muffles into Dimitri's throat, spilling warmth across their stomachs. His arms wind around Dimitri's neck, fingers digging into his nape as he still moves against him, riding out his orgasm as long as he can. Dimitri follows shortly, falling apart when Sylvain clenches down, a growl rumbling from his chest. He covers Sylvain's back in thick spurts, overfilling him inside, feeling his come trickle down Sylvain's thighs once he stops grinding into him.

Their chests billow as they struggle to catch their breaths, the ocean waves still lapping up against them. Dimitri moves his hand to cup some water in his palm, attempting to clean Sylvain's back up as best he can as he softens inside him. Sylvain shifts with a small whine, pulling up, and Dimitri's cocks recede as he settles back into his lap. Dimitri settles his hands at Sylvain's back, smoothing his fingers gently along his skin, trying to keep his claws away as he nuzzles against Sylvain's hair, letting him keep his face tucked against his neck.

"I planned poorly," Sylvain mumbles a moment later, words slurred.

"Mm?"

"I don't want you to go now," he says, pulling back just far enough to press a flurry of close-mouthed kisses to Dimitri's cheek. 

Dimitri's hands press tighter against his back, pressing Sylvain closer. He doesn't particularly feel like leaving Sylvain now, either. At the possessive grip against his back, Sylvain chuckles lowly, lips brushing along the fin framing the side of his face. 

"I suppose I have to, though. Dedue will come looking for you otherwise, right?"

Dimitri doesn't want to agree—he could spend the rest of his days here, with Sylvain nestled close, the waves brushing against them, and want nothing more. Sylvain's right, though. Dedue will search for him if he’s late, and Dimitri is certain that Felix and Ingrid would hunt him all the way to the Kingdom if anything happened to Sylvain.

He releases his grip, bringing a hand up, gingerly stroking his knuckles down Sylvain's jaw, smiling when Sylvain tilts his chin to kiss against the scales, humming happily.

"You'll get sunburned if you stay much longer," Dimitri murmurs.

Sylvain snorts, palms flat on Dimitri's chest, squeezing lightly before he straightens his back. "It's going to be a bitch of a walk back to the jeep," he declares. "But, yeah, I will. Didn't think to bring sunscreen."

"Just lube?"

"And towels," Sylvain tells him, leaning in to kiss him. "Lots of them." He looks down at Dimitri's tail, where their mess is barely getting reached by the water. "I'll need them."

**Author's Note:**

> happy birthday, TK, no one else look at me


End file.
